(CNN) - A new Gallup survey indicates that the congressional approval rating has dropped to its lowest point ever–16%–in a midterm election year since such ratings were first measured by the organization in 1974.

That sets the stage for potentially big turnover this fall in Congress. Gallup notes that in midterm years when the congressional job approval is low, there tends to be more shake-up at the voting booths.

(CNN) - Conservative Rep. Raúl Labrador of Idaho announced Friday he will campaign to become House majority leader, a position soon to be vacated by outgoing Rep. Eric Cantor.

"I want a House Leadership team that reflects the best of our conference," Labrador said in a statement. "Americans don't believe their leaders in Washington are listening and now is the time to change that."

(CNN) - Rep. Eric Cantor is expected to relinquish his leadership position as the No. 2 House Republican after losing his Virginia primary in a stunning upset, a senior GOP source tells CNN's Dana Bash.

Cantor is expected to step aside as majority leader on July 31. The decision sets up a leadership scramble among Republicans in the House, which is led by Speaker John Boehner of Ohio.

(CNN) - It got ugly pretty quickly in the Senate battle in Iowa, a crucial contest that could decide whether the Republicans take control of the chamber in the midterms.

The campaign of Republican nominee Joni Ernst Thursday charged that the Democratic nominee in the race, Rep. Bruce Braley, is "degrading women by comparing Joni Ernst to a 'chick' in his latest campaign ad."FULL POST

Jackson, Mississippi (CNN) – It's unclear how Tuesday's GOP Senate race in Mississippi will end, but the race has no doubt been close–and ugly–in the final stretch.

With 87% of the state's precincts reporting as of 11 p.m. ET, state Sen. Chris McDaniel was narrowly ahead of incumbent Sen. Thad Cochran, 49.9% to 48.4%, according to numbers compiled by The Associated Press.

In Iowa, CNN projects state Sen. Joni Ernst, who garnered support from Mitt Romney and Sarah Palin, will win the GOP primary for the U.S. Senate seat.

Tuesday is the biggest single day of primary voting this year, with eight states holding contests from coast to coast. But the two races that are grabbing the most attention are the contests in Mississippi and Iowa.

(CNN) - More than 24 hours after Army Sgt. Bowe Bergdahl's release, Rep. Buck McKeon, chairman of the Armed Services Committee, said he still has not been briefed by administration officials on the swap.

(CNN) - The House on Thursday approved a bipartisan measure that would provide more money for background checks on gun buyers nearly a week after a mass murder in California left seven people dead, including the killer.

The Republican-led chamber added $19.5 million to expand the National Instant Criminal Background Check System, which is a federal database that states access when processing gun sales.

(CNN) - Over three dozen members of Congress want the government to ensure the humane treatment of orca whales and other marine animals in captivity, following an outcry sparked by the documentary "Blackfish."

The letter, released Thursday and signed by 37 Democrats and one Republican to Agriculture Secretary Tom Vilsack, cites outdated regulations protecting those sea mammals and asserts that the current rules don’t reflect “updated science."